Display device having dummy and reflective regions

ABSTRACT

A display device includes a substrate, a thin film transistor on the substrate, an interlayer insulating layer on the thin film transistor, an electrode on the interlayer insulating layer, the electrode including an emission region, a contact region overlapping the thin film transistor, and a dummy region protruding from the emission region in a direction different from the contact region, and an emission layer on the electrode, the emission region of the electrode overlapping the emission layer.

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2018-0028279, filed on Mar. 9, 2018, inthe Korean Intellectual Property Office, and entitled: “Display Device,”is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The present disclosure relates to a display device.

2. Description of the Related Art

Recently, an organic light-emitting diode (OLED) display has attractedattention as a device for displaying an image. Since the OLED displayhas a self-emission characteristic and does not require an additionallight source, unlike a liquid crystal display device, it is possible toreduce thickness and weight thereof. Further, the OLED display hashigh-quality characteristics, e.g., low power consumption, highluminance, and high response speed.

SUMMARY

An exemplary embodiment provides a display device including a substrate,a thin film transistor configured to be positioned on the substrate, aninterlayer insulating layer configured to be positioned on the thin filmtransistor, an electrode configured to be positioned on the interlayerinsulating layer, and an emission layer configured to be positioned onthe electrode, wherein the electrode may include an emission regionoverlapping the emission layer, a contact region overlapping the thinfilm transistor, and a dummy region protruding from the emission regionin a direction different from the contact region.

The dummy region and the contact region may be symmetrically disposedwith respect to the emission region.

The interlayer insulating layer may include a first hole overlapping thecontact region, and a groove overlapping the dummy region, while thecontact region and the thin film transistor are connected through thefirst hole.

Thicknesses of the emission region, the contact region, and the dummyregion may be substantially the same.

The display device may further include a pixel defining layer configuredto be positioned on the electrode, wherein the emission layer mayinclude a first emission layer that emits light having a firstwavelength, a second emission layer that emits light having a secondwavelength, and a third emission layer that emits light having a thirdwavelength, the pixel defining layer may include a first openingoverlapping the first emission layer, a second opening overlapping thesecond emission layer, and a third opening overlapping the thirdemission layer, and the electrode may include a first electrodeoverlapping the first emission layer, a second electrode overlapping thesecond emission layer, and a third electrode overlapping the thirdemission layer.

The first electrode may include a first emission region, a first contactregion, and a first dummy region, the second electrode may include asecond emission region, a second contact region, and a second dummyregion, and the third electrode may include a third emission region, athird contact region, and a third dummy region.

The first emission layer and the third emission layer, and the secondemission layer, may be positioned at different sides with respect to animaginary line connecting the first contact region, the second contactregion, and the third contact region that are adjacent to each other.

At least one of the first dummy region, the second dummy region, and thethird dummy region, and the remainder thereof, may be positioned atdifferent sides with respect to an imaginary line connecting the firstcontact region, the second contact region, and the third contact regionthat are adjacent to each other.

The interlayer insulating layer may include a first interlayerinsulating layer positioned on the thin film transistor, and a secondinterlayer insulating layer positioned on the first interlayerinsulating layer.

The first hole may pass through the first interlayer insulating layerand the second interlayer insulating layer, and the groove may passthrough the second interlayer insulating layer.

The contact region may contact the drain electrode through the firsthole, and the dummy region may contact the first interlayer insulatinglayer through the groove.

The dummy region may be spaced apart from the emission region.

The display device may include a plurality of second electrodes, atleast one of the plurality of second electrodes may include the contactregion, the emission region, and the dummy region, and the remainder ofthe plurality of second electrodes may include the contact region andthe emission region.

The electrode may include a reflective region.

The contact region, the dummy region, and the reflective region may beformed to be symmetrical with respect to the emission region.

The display device may include a common electrode positioned on theemission layer, a thin film encapsulation layer positioned on the commonelectrode, and at least one of a light blocking member and a colorfilter positioned on the thin film encapsulation layer.

Another embodiment provides a display device including a substrate, athin film transistor configured to be positioned on the substrate, aninterlayer insulating layer configured to be positioned on the thin filmtransistor, an electrode configured to be positioned on the interlayerinsulating layer, and an emission layer configured to be positioned onthe electrode, wherein the electrode may include an emission regionoverlapping the emission layer, a contact region overlapping the thinfilm transistor, and a dummy region protruding from the emission region,and the contact region and the dummy region are depressed from an uppersurface of the interlayer insulating layer.

The dummy region and the contact region may be formed to protrude indifferent directions in a plan view with respect to the emission region.

A height of the depressed dummy region may be equal to or smaller thanthat of the depressed contact region.

Thicknesses of the emission region, the contact region, and the dummyregion may be substantially the same.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of ordinary skill in the art bydescribing in detail exemplary embodiments with reference to theattached drawings, in which:

FIG. 1 illustrates a schematic top plan view of a display deviceaccording to an exemplary embodiment.

FIG. 2 illustrates a cross-sectional view taken along line II-II′ ofFIG. 1.

FIG. 3 illustrates a cross-sectional view of one pixel according to anexemplary embodiment.

FIG. 4 illustrates a cross-sectional view of one pixel according to anexemplary embodiment.

FIG. 5 illustrates a schematic top plan view of a display deviceaccording to an exemplary embodiment.

FIG. 6 illustrates a schematic top plan view of one pixel according toan exemplary embodiment.

FIG. 7 illustrates a cross-sectional view taken along line VII-VII′ ofFIG. 6.

FIG. 8 illustrates a cross-sectional view of one pixel according to anexemplary embodiment.

FIG. 9 illustrates an image observed when light of a surface lightsource is reflected on a display device according to an exemplaryembodiment.

FIG. 10 illustrates an image observed when light of a surface lightsource is reflected on a display device according to a comparativeexample.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. In addition, it will also beunderstood that when a layer is referred to as being “between” twolayers, it can be the only layer between the two layers, or one or moreintervening layers may also be present. Like reference numerals refer tolike elements throughout.

Further, in the specification, the word “on” or “above” means positionedon or below the object portion, and does not necessarily mean positionedon the upper side of the object portion based on a gravitationaldirection. In addition, unless explicitly described to the contrary, theword “comprise” and variations such as “comprises” or “comprising” willbe understood to imply the inclusion of stated elements but not theexclusion of any other elements. Also, throughout the specification, thephrase “on a plane” means viewing a target portion from the top, and thephrase “on a cross-section” means viewing a cross-section formed byvertically cutting a target portion from the side.

Hereinafter, a display device according to an exemplary embodiment willbe described with reference to FIG. 1 and FIG. 2. FIG. 1 illustrates aschematic top plan view of a plurality of light-emitting elementsincluded in a display device according to an exemplary embodiment, andFIG. 2 illustrates a cross-sectional view taken along line II-II′ ofFIG. 1.

Referring to FIG. 1, a display device according to an exemplaryembodiment includes a first light-emitting element R, a secondlight-emitting element G, and a third light-emitting element B. Thefirst light-emitting element R includes a first electrode 191R and afirst emission layer 370R, the second light-emitting element G includesa second electrode 191G and a second emission layer 370G, and the thirdlight-emitting element B includes a third electrode 191B and a thirdemission layer 370B.

The first electrode 191R includes a first emission region (191 m_R), afirst contact region (191 a_R), and a first dummy region (191 bR). Thesecond electrode 191G includes a second emission region (191 m_G), asecond contact region (191 a_G), and a second dummy region (191 b_G).The third electrode 191B includes a third emission region (191 m_B), athird contact region (191 a_B), and a third dummy region (191 b_B). Inthe specification, the emission region is referred to as a regionoverlapping the emission layer in one electrode, the contact region isreferred to as a region substantially directly connected to anotherwire, electrode, or the like in one electrode, and the dummy region isreferred to as a region that is not directly connected to another wire,electrode, or the like in one electrode and protrudes from the emissionregion. Details thereof will be described below.

As illustrated in FIG. 1, a contact region 191 a and a dummy region 191b may protrude in different directions based on an emission region 191 min a plan view. For example, the first dummy region (191 b_R) mayprotrude in a +D2 direction, and the first contact region (191 a_R) mayprotrude in a −D2 direction. In addition, the second contact region (191a_G) may protrude in the +D2 direction, and the second dummy region (191b_G) may protrude in the −D2 direction. The third dummy region (191 b_B)may protrude in the +D2 direction, and the third contact region (191 aB) may protrude in the −D2 direction. Embodiments are not limited to theprotruding directions, and the respective regions may protrude in anydifferent direction.

As illustrated in FIG. 1, the contact region 191 a and the dummy region191 b, e.g., in each of the first through third light-emitting elementsR through B, may be disposed to be symmetrical based on the emissionregion 191 m, e.g., in a top view. For example, the contact region 191 aand the dummy region 191 b, e.g., in each of the first through thirdlight-emitting elements R through B, may be symmetrical based on an axis(X-axis) parallel to a D1 direction, e.g., the contact region 191 a andthe dummy region 191 b may be symmetrical with respect to a symmetryaxis crossing a center of a corresponding emission layer 370 along thedirection D1 from a top view. However, the symmetrical disposition isnot limited thereto.

A first pair of the first emission layer 370R and third emission layer370B, and the second emission layer 3706, may be positioned at differentsides with respect to an imaginary first line VL1 that connects thefirst contact region (191 a_R), the second contact region (191 a_G), andthe third contact region (191 a_B) according to the exemplaryembodiment. For example, the first pair of the first emission layer 370Rand the third emission layer 370B may be positioned in the +D2 directionrelative to the imaginary first line VL1, and the second emission layer370G may be positioned in the −D2 direction relative to the imaginaryfirst line VL1. The imaginary first line VL1 may extend in the D1direction.

In addition, a second pair of the first emission layer 370R and thirdemission layer 370B, and the second emission layer 370G, may bepositioned at different sides with respect to an imaginary second lineVL2 that connects the first dummy region (191 b_R), the second dummyregion (191 b_G), and the third dummy region (191 b_B). For example, thesecond pair of the first emission layer 370R and the third emissionlayer 370B may be positioned in the −D2 direction relative to theimaginary second line VL2, and the second emission layer 370G may bepositioned in the +D2 direction relative to the imaginary second lineVL2. The imaginary second line VL2 may extend in the D1 direction. Forexample, as illustrated in FIG. 1, the second emission layer 370G may bein a center between the first and second pairs of the first emissionlayer 370R and third emission layer 370B.

At least one of the first dummy region (191 b_R), the second dummyregion (191 b_G), and the third dummy region (191 b_B) may be positionedat another side based on the imaginary first line VL1 that connects thefirst contact region (191 a_R), the second contact region (191 a_G), andthe third contact region (191 a_B) according to the exemplaryembodiment. In the imaginary first line VL1 formed by the firstlight-emitting element R, the second light-emitting element G, and thethird light-emitting element B, the first dummy region (191 b_R) of thefirst light-emitting element R and the third dummy region (191 b_B) ofthe third light-emitting element B, and the second dummy region (191b_G) of the second light-emitting element G, may be positioned atdifferent sides based on the imaginary first line VL1. That is, thefirst dummy region (191 b_R) of the first light-emitting element R andthe third dummy region (191 b_B) of the third light-emitting element Bmay be positioned in the +D2 direction based on the imaginary first lineVL1, and the second dummy region (191 b_G) of the second light-emittingelement G may be positioned in the −D2 direction based on the imaginaryfirst line VL1.

Alternatively, at least one of the first contact region (191 a_R), thesecond contact region (191 a_G), and the third contact region (191 a_B)may be positioned at another side based on the imaginary second line VL2that connects the first dummy region (191 b_R), the second dummy region(191 b_G), and the third dummy region (191 b_B). In the imaginary secondline VL2 formed by the first light-emitting element R, the secondlight-emitting element G, and the third light-emitting element B, thefirst contact region (191 a_R) of the first light-emitting element R andthe third contact region (191 a_B) of the third light-emitting elementB, and the second contact region (191 a G) of the second light-emittingelement G, may be positioned at different sides based on the imaginarysecond line VL2. That is, the first contact region (191 a_R) of thefirst light-emitting element R and the third contact region (191 a_B) ofthe third light-emitting element B may be positioned in the −D2direction based on the imaginary second line VL2. The second contactregion (191 a_G) of the second light-emitting element G may bepositioned in the +D2 direction based on the imaginary second line VL2.

In a comparative electrode, i.e., which does not include a dummy region,purple light may be emitted in a 1 o'clock direction while first redlight R1 reflected by the first contact region (191 a_R) and first bluelight B1 reflected by the third contact region (191 a_B) is summed. Inaddition, in the second contact region (191 a_G), first green light G1may be reflected in a 5 o'clock direction, thus emitting green light.Therefore, purple light may be viewed in some regions and green lightmay be viewed in other regions, which is referred to as a reflectedcolor separation phenomena.

In contrast, in the display device according to the exemplaryembodiment, since dummy regions are formed on the pixel electrode 191opposite the contact regions, white light may be emitted while the firstred light R1 reflected by the first contact region (191 a_R), the secondgreen light G2 reflected by the second dummy region (191 b_G), and thefirst blue light B1 reflected by the third contact region are summed(i.e., the three arrows pointing up in FIG. 1). In addition, white lightmay be emitted while the second red light R2 reflected by the firstdummy region (191 b_R), the first green light G1 reflected by the secondcontact region (191 a_G), and the second blue light B2 reflected by thethird dummy region (191 b_B) are summed (i.e., the arrows pointing downin FIG. 1). Even though reflection occurs by a surface light source orpoint light source in a state in which a display device is not driven,it is possible to reduce a reflected color separation phenomenon and toemit white light through a dummy region and a contact region that aresymmetrically disposed.

Hereinafter, a stacked structure of a display device according to anexemplary embodiment will be specifically described with reference toFIG. 2 together with FIG. 1. It is noted that the structure of the pixelelectrode in FIG. 2 may be applicable to either of the first throughthird electrodes 191R through 191B in FIG. 1.

Referring to FIG. 2, a buffer layer 111 may be positioned on a substrate110. The substrate 110 may be an insulating substrate including, e.g.,glass, polymer, stainless steel, or the like. The substrate 110 may beflexible, stretchable, foldable, bendable, or rollable. Since thesubstrate 110 is flexible, stretchable, foldable, bendable, or rollable,the display device may be wholly flexible, stretchable, foldable,bendable, or rollable.

The buffer layer 111 may overlap a front surface of the substrate 110.The buffer layer 111 may include an inorganic material, e.g., a siliconoxide (SiO_(x)), a silicon nitride (SiN_(k)), and the like. The bufferlayer 111 may have a single layer structure or a multiple layerstructure.

The buffer layer 111 may flatten one surface of the substrate 110, ormay prevent diffusion of impurities and penetration of moisture or thelike that degrades characteristics of a semiconductor layer 151, whichwill be described later. In some exemplary embodiments, the buffer layer111 may be omitted.

The semiconductor layer 151 may be positioned on the buffer layer 111.The semiconductor layer 151 may include a channel region 154 and asource region 153 and a drain region 155 that are doped, and are onopposite side of the channel region 154. The semiconductor layer 151 mayinclude, e.g., polysilicon, amorphous silicon, or an oxidesemiconductor.

A gate insulating layer 140 may be positioned on the semiconductor layer151. The gate insulating layer 140 may be positioned to overlap a frontsurface of the substrate 110. The gate insulating layer 140 may includean inorganic insulating material, e.g., a silicon oxide (SiO_(x)), asilicon nitride (SiN_(x)), and the like.

A gate conductor including a gate electrode 124 of a thin filmtransistor may be positioned on the gate insulating layer 140. The gateelectrode 124 may overlap the channel region 154 of the semiconductorlayer 151.

An insulating layer 160 including an inorganic insulating material or anorganic insulating material may be positioned on the gate electrode 124.Data conductors including a source electrode 173 and a drain electrode175 of the thin film transistor, and a data line, a signal line, and thelike may be positioned on the insulating layer 160. The source electrode173 and the drain electrode 175 may be respectively connected to thesource region 153 and the drain region 155 of the semiconductor layer151 through contact holes 163 and 165 provided in the insulating layer160 and the gate insulating layer 140.

The gate electrode 124, the source electrode 173, and the drainelectrode 175 form a thin film transistor together with thesemiconductor layer 151. The shown thin film transistor may be a thinfilm transistor included in one pixel of the organic light-emittingdiode display. The shown thin film transistor may be referred to as atop-gate transistor since the gate electrode 124 is positioned above thesemiconductor layer 151. However, a structure of the transistor is notlimited thereto, and may be variously modified. For example, thetransistor may be a bottom-gate transistor of which a gate electrode ispositioned below a semiconductor layer.

An interlayer insulating layer 180 may be positioned on the insulatinglayer 160 and the data conductors. The interlayer insulating layer 180may serve to remove and flatten a step and to improve light-emittingefficiency of a light-emitting element to be formed thereon. Theinterlayer insulating layer 180 may overlap and cover the thin filmtransistor.

The interlayer insulating layer 180 may include, e.g., an organicinsulating material. The organic insulating material may include, e.g.,polyimide, polyamide, polyacrylate, polyphenylene ether, polyphenylenesulfide, unsaturated polyester, an epoxy resin, a phenolic resin, andthe like, but is not limited thereto.

The interlayer insulating layer 180 is provided with a first hole 185 aoverlapping the contact region 191 a and a groove 185 b overlapping thedummy region 191 b. A height h1 of the first hole 185 a and a height h2of the groove 185 b along the third direction D3 may be different fromeach other. For example, the height 111 of the first hole 185 a may begreater than twice the height h2 of the groove 185 b.

An electrode 191 is positioned on the interlayer insulating layer 180.The pixel electrode 191 may include the emission region 191 moverlapping an emission layer 370, the contact region 191 a overlappingthe first hole 185 a, and the dummy region 191 b overlapping the groove185 b. The electrode 191 may be a pixel electrode, and may be connectedto the drain electrode 175 of the thin film transistor through thecontact region 191 a and the first hole 185 a provided in the interlayerinsulating layer 180.

The pixel electrode 191 may include a reflective conductive material, atransflective conductive material, or a transparent conductive material.For example, the entirety of the pixel electrode 191, i.e., the emissionregion 191 m, the contact region 191 a, and the dummy region 191 b mayall include a same material. For example, the pixel electrode 191 mayinclude one of a transparent conductive material, e.g., an indium tinoxide (ITO) and an indium zinc oxide (IZO), and a metal, e.g., lithium(Li), calcium (Ca), aluminum (Al), silver (Ag), magnesium (Mg), and gold(Au).

For example, the emission region 191 m, the contact region 191 a, andthe dummy region 191 b of the pixel electrode 191 may be continuous andintegral with each other. For example, as was discussed previously andas illustrated in FIG. 2, the contact region 191 a and the dummy region191 b may be at opposite sides of the emission region 191 m along thesecond direction D2. Thicknesses of the emission region 191 m, thecontact region 191 a, and the dummy region 191 b in the pixel electrode191 may be substantially the same. The contact region 191 a and thedummy region 191 b may have the same thickness even in a regionoverlapping the contact hole.

The contact region 191 a and the dummy region 191 b may have a depressedshape with respect to an upper surface of the interlayer insulatinglayer 180. The contact region 191 a may have a depressed shape in aregion overlapping the first hole 185 a, i.e., to electrically contactthe thin film transistor. The dummy region 191 b may have a depressedshape in a region overlapping the groove 185 b, e.g., the dummy region191 b may only partially extend into the interlayer insulating layer 180without contacting a bottom surface of the interlayer insulating layer180.

In detail, the height h1 at which the contact region 191 a is depressedand the height h2 at which the dummy region 191 b is depressed, may bedifferent. The height h1 at which the contact region 191 a is depressedmay be greater than, e.g., about twice, the height h2 at which the dummyregion 191 b is depressed.

As described above, the pixel electrode 191 according to the exemplaryembodiment may include the first electrode 191R overlapping the firstemission layer 370R, the second electrode 191G overlapping the secondemission layer 370G, and the third electrode 191B overlapping the thirdemission layer 370B. Each of the first electrode 191R, the secondelectrode 191G, and the third electrode 191B may include the emissionregion, the contact region, and the dummy region that are describedabove with respect to FIG. 2. Since this configuration has beendescribed with reference to FIG. 1, it will be omitted below.

A pixel defining layer 360 may be positioned on the interlayerinsulating layer 180 and the pixel electrode 191. The pixel defininglayer 360 may overlap some of the pixel electrode 191.

The pixel defining layer 360 is provided with an opening 361 overlappingthe pixel electrode 191, e.g., overlapping the emission region 191 m ofthe pixel electrode 191. The opening 361 of the pixel defining layer 360may define a region corresponding to a pixel. The opening 361 mayinclude a first opening 361R overlapping the first emission layer 370R,a second opening 361G overlapping the second emission layer 370G, and athird opening 361B overlapping the third emission layer 370B.

The opening 361 may have, e.g., a polygonal shape or a circular shape,in a plan view, and the polygonal shape may include, e.g., aquadrangular shape, a triangular shape, a pentagonal shape, a hexagonalshape, a heptagonal shape, and an octagonal shape. Even if the opening361 has a polygonal shape, it may have a polygonal shape close to acircular shape according to a process. The pixel defining layer 360 mayinclude an organic insulating material, e.g., polyimide, polyacrylate,and polyamide, but is not limited thereto.

The emission layer 370 is positioned on the pixel electrode 191. Theemission layer 370 includes an emission region. The emission layer 370may additionally include at least one of a hole injection region, a holetransport region, an electron injection region, and an electrontransport region.

The emission layer 370 may include a material for intrinsicallydisplaying light of primary colors, e.g., red, green, and blue. Theemission layer 370 may include the first emission layer 370R foremitting light having a first wavelength, the second emission layer 370Gfor emitting light having a second wavelength, and the third emissionlayer 370B for emitting light having a third wavelength. For example,the light having the first wavelength may be red, the light having thesecond wavelength may be green, and the light having the thirdwavelength may be blue.

In addition, a structure in which a plurality of organic material layersfor emitting light of different colors are stacked may be provided.Moreover, an inorganic material for emitting light, e.g., red, green,and blue light, may be included therein.

A common electrode 270 for transmitting a common voltage is positionedon the emission layer 370. The common electrode 270 may include atransparent conductive material, e.g., an indium tin oxide (ITO) and anindium zinc oxide (IZO). The common electrode 270 may be formed to havelight transmittance by thinly stacking a metal, e.g., calcium (Ca),barium (Ba), magnesium (Mg), aluminum (Al), or the like. At least onepassivation layer or functional layer may be formed on the commonelectrode 270.

The pixel electrode 191, the emission layer 370, and the commonelectrode 270 form a light-emitting device D which is a light-emittingdiode (LED). For example, the pixel electrode 191 may be an anode whichis a hole injection electrode, and the common electrode 270 may be acathode which is an electron injection electrode. In another example,the pixel electrode 191 may be the cathode, and the common electrode 270may be the anode. Holes and electrons are injected into the emissionlayer 370 from the pixel electrode 191 and the common electrode 270,respectively, and exitons in which the injected holes and electrons arecombined enter a ground state from an excited state to emit light.

A thin film encapsulation layer 400 may be positioned on the commonelectrode 270. The thin film encapsulation layer 400 may include aplurality of inorganic or organic layers, or may have a structure inwhich the inorganic layers and the organic layers are alternatelystacked.

The inorganic layer may include a metal oxide or a metal nitride. Forexample, the inorganic layer may include one of SiN_(x), Al₂O₃, SiO₂,and TiO₂. The organic layer may include a polymer, and may include,e.g., one of polyethylene terephthalate, polyimide, polycarbonate,epoxy, polyethylene, and polyacrylate.

In the present specification, the exemplary embodiment in which the thinfilm encapsulation layer 400 is positioned directly on the commonelectrode 270 is illustrated, but embodiments are not limited thereto.For example, ac separate filling material, an adhesive material, or thelike may be positioned between the common electrode 270 and the thinfilm encapsulation layer 400.

Hereinafter, a display device according to an exemplary embodiment willbe described with reference to FIG. 3 to FIG. 5. FIG. 3 illustrates across-sectional view of one pixel according to an exemplary embodiment,FIG. 4 illustrates a cross-sectional view of one pixel according to anexemplary embodiment, and FIG. 5 illustrates a schematic top plan viewof a display device according to an exemplary embodiment. Descriptionsfor constituent elements that are identical or similar to those of theexemplary embodiments described above with reference to FIG. 1 and FIG.2 will be omitted.

Referring to FIG. 3, the interlayer insulating layer 180 according tothe exemplary embodiment includes a first interlayer insulating layer180 a and a second interlayer insulating layer 180 b. The firstinterlayer insulating layer 180 a may be positioned on the thin filmtransistor, e.g., on the source electrode 173 and the drain electrode175. The second interlayer insulating layer 180 b may be positioned onthe first interlayer insulating layer 180 a. The first interlayerinsulating layer 180 a and the second interlayer insulating layer 180 bmay contain the same material or may contain different materials.

The first hole 185 a may pass through the first interlayer insulatinglayer 180 a and the second interlayer insulating layer 180 b. The groove185 b may pass through the second interlayer insulating layer 180 b,e.g., the groove 185 b may not extend into the first interlayerinsulating layer 180 a. The contact region 191 a may be connected to thethin film transistor through the first hole 185 a, and the dummy region191 b may contact the first interlayer insulating layer 180 a throughthe groove 185 b.

Referring to FIG. 4, the emission region 191 m and the dummy region 191b according to the exemplary embodiment may be spaced apart from eachother, e.g., a portion of the pixel defining layer 360 may separate theemission region 191 m and the dummy region 191 b. The emission region191 m and the dummy region 191 b may not be connected, and no voltagemay be separately applied to the dummy region 191 b. No voltage isseparately applied to the dummy region 191 b, thereby preventingcapacitance from being unnecessarily formed between the dummy region 191b and another signal line or electrode.

Referring to FIG. 5, a display device according to an exemplaryembodiment includes the first light-emitting element R, the secondlight-emitting element G, and the third light-emitting element B. Thefirst electrode 191R includes the first emission region (191 m_R), thefirst contact region (191 a_R), and the first dummy region (191 b_R).The third electrode 191B includes the third emission region (191 m_B),the third contact region (191 a_B), and the third dummy region (191b_B).

Some of a plurality of the second electrodes 191G according to theexemplary embodiment include the second emission region (191 m_G), thesecond contact region (191 a_G), and the second dummy region (191 b_G).In addition, the remainder of the plurality of the second electrodes191G include the second emission region (191 m_G) and the second contactregion (191 a_G), e.g., some of the plurality of second electrodes 191Gaccording to the exemplary embodiment may not include the second dummyregion (191 b_G).

As shown in FIG. 5, in the display device according to an exemplaryembodiment, the numbers of the first light-emitting elements R, thesecond light-emitting elements G. and the third light-emitting elementsB per unit area may be different. The number of the secondlight-emitting elements G per unit area may be larger than that of thefirst light-emitting elements R per unit area, and the number of thesecond light-emitting elements G per unit area may be larger than thatof the third light-emitting elements B per unit area. When all of theplurality of second electrodes 191G include the dummy region 191 b, areflection degree of green light may be greater than that of red or bluelight. Therefore, as illustrated in FIG. 5, some of the secondelectrodes 191G according to the exemplary embodiment may not includethe dummy region (191 b G).

Hereinafter, a display device according to an exemplary embodiment willbe described with reference to FIG. 6 to FIG. 8. FIG. 6 illustrates aschematic top plan view of one pixel according to an exemplaryembodiment, FIG. 7 illustrates a cross-sectional view taken along lineVII-VII′ of FIG. 6, and FIG. 8 illustrates a cross-sectional view of onepixel according to an exemplary embodiment.

Referring to FIG. 6 and FIG. 7, a light blocking member 220 may bepositioned on the thin film encapsulation layer 400. The light blockingmember 220 according to the exemplary embodiment may be positioned tooverlap part of the pixel electrode 191. In addition, the light blockingmember 220 may overlap part of the pixel defining layer 360. An area ofan opening 221 of the light blocking member 220 may be larger than thatof the opening 361 of the pixel defining layer 360.

A pixel electrode 191′ according to the exemplary embodiment may includethe emission region 191 m, the contact region 191 a, the dummy region191 b, and a reflective region 191 c. The contact region 191 a, thedummy region 191 b, and the reflective region 191 c may be symmetricalwith respect to the emission region 191 m.

The contact region 191 a, the dummy region 191 b, and the reflectiveregion 191 c that do not overlap the light blocking member 220 may besymmetrical with respect to the emission region 191 m. The reflectiveregions 191 c not overlapping the light blocking member 220 may besymmetrical with respect to the D2 direction, and the contact region 191a and the dummy region 191 b may be symmetrical with respect to the D1direction. Light reflected by the contact region 191 a, the dummy region191 b, and the reflective region 191 c is not reflected to be biased inone direction, so that the reflected color separation phenomenon may bereduced.

In the present specification, the contact region 191 a, the dummy region191 b, and the reflective region 191 c are symmetrically illustrated,but embodiments are not limited thereto. For example, the contact region191 a, and any structure in which areas of the dummy region 191 b andthe reflective region 191 c that do not overlap the light blockingmember 220 are substantially the same is possible.

Referring to FIG. 8, a display device according to an exemplaryembodiment may include the light blocking member 220 and a color filter230 that are positioned on the thin film encapsulation layer 400. Thelight blocking member 220 may overlap the pixel defining layer 360, andthe color filter 230 may overlap the emission layer 370.

The color filter 230 may include a resin composition displaying the samecolor as the light emitted from the emission layer 370. For example,when red light is emitted from the emission layer 370, the color filter230 may be a red color filter, when green light is emitted from theemission layer 370, the color filter 230 may be a green color filter,and when blue light is emitted from the emission layer 370, the colorfilter 230 may be a blue color filter.

Hereinafter, images according to an exemplary embodiment and acomparative example will be described with reference to FIG. 9 and FIG.10. FIG. 9 illustrates an image according to an exemplary embodiment,and FIG. 10 illustrates an image according to a comparative example.

Referring to the image shown in FIG. 9, it can be seen that the colorseparation phenomenon does not occur even when light of a surface lightsource is reflected on the display device according to the exemplaryembodiment. In contrast, in the display device according to thecomparative example, as shown in the photograph of FIG. 10, it can beseen that the image is blurry as green light or purple light (redlight+blue light) is viewed by an external surface light source.Therefore, in the display device according to the exemplary embodiment,it can be confirmed that red light, green light, and blue light areseparated and reflected by an external surface light source or a pointlight source such that the reflected color separation phenomenon viewedby the user's eyes is reduced.

By way of summation and review, embodiments provide a display devicethat includes a pixel electrode with a dummy region opposite a contactregion, thereby reducing a reflected color separation phenomenon causedby an external surface light source or point light source in a state inwhich the display device is not driven.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. A display device, comprising: a substrate; a thinfilm transistor on the substrate; an interlayer insulating layer on thethin film transistor; an electrode on the interlayer insulating layer,the electrode including: an emission region, a contact regionoverlapping the thin film transistor, and a dummy region protruding fromthe emission region in a direction different from the contact region;and an emission layer on the electrode, the emission region of theelectrode overlapping the emission layer, wherein the dummy region andthe contact region are symmetrically disposed with respect to theemission region in a plan view, and the interlayer insulating layerincludes a groove overlapping the dummy region.
 2. The display device asclaimed in claim 1, wherein the interlayer insulating layer includes afirst hole overlapping the contact region, the contact region, and thethin film transistor being connected through the first hole.
 3. Thedisplay device as claimed in claim 2, wherein the interlayer insulatinglayer further includes: a first interlayer insulating layer on the thinfilm transistor; and a second interlayer insulating layer on the firstinterlayer insulating layer.
 4. The display device as claimed in claim3, wherein: the first hole passes through the first interlayerinsulating layer and the second interlayer insulating layer, and thegroove passes through the second interlayer insulating layer.
 5. Thedisplay device as claimed in claim 3, wherein the dummy region contactsthe first interlayer insulating layer through the groove.
 6. The displaydevice as claimed in claim 1, wherein thicknesses of the emissionregion, the contact region, and the dummy region are substantially thesame.
 7. The display device as claimed in claim 1, further comprising: apixel defining layer on the electrode, wherein the emission layerincludes: a first emission layer to emit light having a firstwavelength, a second emission layer to emit light having a secondwavelength, and a third emission layer to emit light having a thirdwavelength; wherein the pixel defining layer includes: a first openingoverlapping the first emission layer, a second opening overlapping thesecond emission layer, and a third opening overlapping the thirdemission layer; and wherein the electrode includes: a first electrodeoverlapping the first emission layer, a second electrode overlapping thesecond emission layer, and a third electrode overlapping the thirdemission layer.
 8. The display device as claimed in claim 7, wherein:the first electrode includes a first emission region, a first contactregion, and a first dummy region, the second electrode includes a secondemission region, a second contact region, and a second dummy region, andthe third electrode includes a third emission region, a third contactregion, and a third dummy region.
 9. The display device as claimed inclaim 8, wherein the first emission layer and the third emission layer,and the second emission layer, are positioned at different sides withrespect to an imaginary line connecting the first contact region, thesecond contact region, and the third contact region that are adjacent toeach other.
 10. The display device as claimed in claim 8, wherein atleast one of the first dummy region, the second dummy region, and thethird dummy region, and the remainder thereof, are positioned atdifferent sides with respect to an imaginary line connecting the firstcontact region, the second contact region, and the third contact regionthat are adjacent to each other.
 11. The display device as claimed inclaim 7, wherein: the display device includes a plurality of secondelectrodes, at least one of the plurality of second electrodes includesthe contact region, the emission region, and the dummy region, and aremainder of the plurality of second electrodes includes the contactregion and the emission region.
 12. The display device of claim 1,wherein the dummy region is spaced apart from the emission region. 13.The display device as claimed in claim 1, wherein the electrode includesa reflective region.
 14. The display device as claimed in claim 13,wherein the contact region, the dummy region, and the reflective regionare symmetrical with respect to the emission region.
 15. The displaydevice as claimed in claim 1, further comprising: a common electrode onthe emission layer; a thin film encapsulation layer on the commonelectrode; and at least one of a light blocking member and a colorfilter on the thin film encapsulation layer.
 16. The display device asclaimed in claim 1, wherein the dummy region is in a form of aprotrusion protruding from the emission region in a direction differentfrom the contact region as shown in plan view.
 17. The display device asclaimed in claim 16, wherein the contact region is in a form of aprotrusion overlapping the thin film transistor and protruding from theemission region as shown in plan view.
 18. A display device, comprising:a substrate; a thin film transistor on the substrate; an interlayerinsulating layer on the thin film transistor; an electrode on theinterlayer insulating layer, the electrode including: an emissionregion, a contact region overlapping the thin film transistor, and adummy region protruding from the emission region, the contact region andthe dummy region being depressed from an upper surface of the interlayerinsulating layer; and an emission layer on the electrode, the emissionregion of the electrode overlapping the emission layer, wherein thedummy region and the contact region are symmetrically disposed withrespect to the emission region in a plan view.
 19. The display device asclaimed in claim 18, wherein the dummy region and the contact regionprotrude in different directions in a plan view with respect to theemission region.
 20. The display device as claimed in claim 18, whereina height of the depressed dummy region is equal to or smaller than thatof the depressed contact region.
 21. The display device as claimed inclaim 18, wherein thicknesses of the emission region, the contactregion, and the dummy region are substantially the same.
 22. The displaydevice as claimed in claim 18, wherein the dummy region is in a form ofa protrusion protruding from the emission region in a directiondifferent from the contact region as shown in plan view.
 23. The displaydevice as claimed in claim 22, wherein the contact region is in a formof a protrusion overlapping the thin film transistor and protruding fromthe emission region as shown in plan view.